Functional Description
5.13.10 System Power Supplies, Planes, and Signals
5.13.10.1 Power Plane Control with SLP_S3#, SLP_S4#, SLP_S5# and SLP_M#
The SLP_S3# output signal can be used to cut power to the system core supply, since it
only goes active for the Suspend-to-RAM state (typically mapped to ACPI S3). Power
must be maintained to the ICH10 suspend well, and to any other circuits that need to
generate Wake signals from the Suspend-to-RAM state. During S3 (Suspend-to-RAM)
all signals attached to powered down plans will be tri-stated or driven low, unless they
are pulled via a pull-up resistor.
Cutting power to the core may be done via the power supply, or by external FETs on the
motherboard.
The SLP_S4# or SLP_S5# output signal can be used to cut power to the system core
supply, as well as power to the system memory, since the context of the system is
saved on the disk. Cutting power to the memory may be done via the power supply, or
by external FETs on the motherboard.
The SLP_S4# output signal is used to remove power to additional subsystems that are
powered during SLP_S3#.
SLP_S5# output signal can be used to cut power to the system core supply, as well as
power to the system memory, since the context of the system is saved on the disk.
Cutting power to the memory may be done via the power supply, or by external FETs
on the motherboard.
SLP_M# output signal can be used to cut power to the Controller Link, Clock chip and
SPI flash on a platform that supports Intel AMT.
5.13.10.2 SLP_S4# and Suspend-To-RAM Sequencing
The system memory suspend voltage regulator is controlled by the Glue logic. The
SLP_S4# signal should be used to remove power to system memory rather than the
SLP_S5# signal. The SLP_S4# logic in the ICH10 provides a mechanism to fully cycle
the power to the DRAM and/or detect if the power is not cycled for a minimum time.
Note:
To use the minimum DRAM power-down feature that is enabled by the SLP_S4#
Assertion Stretch Enable bit (D31:F0:A4h bit 3), the DRAM power must be controlled
by the SLP_S4# signal.
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Datasheet
INTEL [ INTEL ]
